Underreamer.



W. WAGNER.

UNDERRBAMER.

APPLICATION FILED FEB. 12. 1913.

Patented Dec. 9, 1913.

2 SHEETS-SHEET 1.

nuenl'oz W Wagnev;

I M attozmug mu H MH W. WAGNER. UNDERREAMER APPLICATION FILED PEB.12.191G

Patented Dec. 9, 1913.

2 SHEET SHEBT 2.

. UNITE STATES OFGE.

WARREN WAGNER, or bv'nxsvnnn'rr, irnxas.

UNDEIRREAMER.

Specification of lflctters .Paten't.

Patented cc. 9, 1913.

Application filed February 12, 1913. Serial No. 746,038.

. drawings.

This invention relates to underreamers such as are employed for reaming wells beneath the lower end of a tube or casing and the invention has for its primary object to generall improve the construction and increase t e operatingefiiciency of a tool of this character, such as is disclosed in my prior Patent Number 1,038,243, issued to me September 10, 1912.

vAnother object of the invention resides in the provision. of improved means for mounting the cutting bits in the mandrel so that t e spreading movement y are securel held against lateral rom their operative positions beneath the lower end of the well casing. 1

Another and more specific object of the invention is to provide a spring pressed plunger or stem mounted in the mandrel and a key connecting the cutting bits to said mandrel and means carried by the cutting bits to prevent their lateral movement or complete disconnection from the mandrel in the event that said key should be broken, thus obviating the loss of the bits.

, Another ob ect of the invention is to provide cutting bits of improved form for tools of this character and a separating web therebetween formed upon the lower end of the mandrel, and means for minimizing the wear upon said web induced by the fric- 'tional contact of the bits therewith.

A further object is to produce an underreamer which is comparatively simple in its construction, and wherein the bits may be readily removed from the mandrel when it is necessary to sharpen the same.

With-the above and other objects in view as will become apparent as the description proceeds, the invention consists in certainconstructions, combinations and arrangements of the parts that I shall hereinafter fully "describe and claim.

For a full understanding of the invention, reference is to be had to the following description and accompanying drawings, in which- Figure 1 is a side elevation of an underrea'mer embodying the present invention; Fig. 2 is a view lookin at right angles to Fig. 1 showin the positions of the cutting bits as the too is being lowered in the well casing; Fig. 3 is a section taken on the line 3-3 of Fig. 1, showing the device in its operative position; Fig. 4 is a section taken on the line 4- 4 of Fig. 3; Fig. 5 is a side elevation of the mandrel the bits being removed; Fig. 6 is a detail perspective view of one of the cuttin bits; and Fig. 7 is a horizontal section 0, the lower ends of the cutting bits.

Referring in detail to the drawings, 5 indicates the stock or mandrel which is longitudinally bored as indicated at 6, the

up er end of said bore being enlarged as at 7 or a purpose which will be later referred to. r

The mandrel is provided upon opposite sides with channels 8 and slots 9 connect these channels with the central longitudinal bore 6. The lower ends of the slots Q are widened or flared as indicated at 10. The opposed walls of the channels 8 are provided with longitudinal guide grooves 11, said grooves gradually widening at their lower open ends as indicated at 12 in Fig. 3. In clined notches or recesses 13 open into the guide grooves 11 at a point intermediate their ends. The lower end of the stock or mandrel iaprovided with a central lon 'tudinally extended web 14, the lower on of which is beveled in o posite directions as indicated at 15. The body of the mandrel upon opposite sides of the channels 10 therein is curved upwardly to roduce the convex bearing faces 16. At t e upper ends of these bearing faces the abrupt downwardly inclined shoulders 17 are formed. The pur pose of this particular construction of the mandrel will become fully apparent as the description proceeds.

The cutting bits illustrated in detail in Fig. 6 each consists of the bit blade or body 18 which is formed upon one end of a lon-" gitudinally extended rectangular shank 19. The outer face of the bit body is slightly inclined outwardly with relation to the lon-' gitudinal axis of the shank andis rounded or convex as shown. These bits are provide upon their-innerfaces and ends with the gradually widening lapping flanges 18 as clearly illustrated in Fig. 7, wherein the bits are shown in the relative positions they assume when disposed in working position beneath the well casing. It will be observed that the edges of these flanges are slightly spaced from the body walls of the bits so that they constitute in conjunction with each other a continuous cutting orscraping edge across the bottom surface of the bits, and thereby effectually cut or break up hard substances at the bottom of the well; Each of the bits is also provided with a flattened face on opposite sides thereof as shown at'20. -The inner opposed faces of the cutting bits are engaged with opposite sides of the depending web plate 1d on the lower end of the mandrel 5, 1

but little or no frictional though they exert the operation of the pressure thereon in device.

At the juncture of the body or cutting blade of the bit with the shank thereof and upon the outer face ance or shoulder 21 is formed. The upper edges of the bit body upon opposite sides of the shank are concave as indicated at 22 and adjacentto the shank at the upper ends of said concave faces, the beveled bearing surfaces "23 are provided. These concave and beveled surfaces of the bit body are complementary to the convex surfaces 16 and the inclined shoulders 17 of the mandrel and bear against the same in the operativepositions of the cutting bits, The shoulders '17 coacting withthe beveled surfaces of the bits prevent outward or lateral movement-of the bits in the rotation of the tool while the convex faces 16 of the mandrel reduce wear upon the depending web 14 to a minimum.

By providing the concave surfaces 22 on the cutting bits to seat against the convex sur-x faces 16 of the mandrel, longitudinal pressure of the cutting bits when in operation tends to force the same outwardly. away from the-central'web 14- and cause the shoulders 23 of the cutting bitsto bear against the shoulders 7 on the mandrel, whereby the wear of the'parts is greatly minimized andthe device as a whole rendered very strong and durable.

Lugs 24: areformed upon the end'of the h nk 19 of each of the cutting bits and prev at their lower wardly and inw r y,

ence to Fig. 3 that -shanks of the cutting clined inwardly toward the body of the "bit ed. A coil spring upper end of this stem within the enlarged ;end 7 of the bore and of the bit, a protuberend of the stem. 28 1s providedwith a rectangular transverse.

34 is broken in 7 this possibleloss of the cutting bits,

wide the mandrel with vat each side thereof.

n s ott aoeaeec ject from opposite faces of said shanks. These lugs are provided with rounded peripheral faces 25 and are adapted to rock upon the inner side walls of the grooves 11 in the stock or mandreL. The shank 19 of each cutting bit is also provided upon the facesthereof whereon the lugs 24 are formed with longitudinal ribs 26, said ribs terminating in spaced relation to the lugs 24. In the insertion of thesebits into the mandrel,

the shanks thereof are disposed approximately at right angles to the longitudinal axis of the mandrel and the lugs 24 passed through the recesses 13 and into the grooves 11. The cutting bits are now moved downand then forced longitudinally so that the lugs 24: thereon are moved into the upper ends of the grooves 11 and the ribs 26 extended into said guide grooves. The lower ends of the channels 8 in the mandrel are widened to permit the ribs 26 of the bit shanks to move through said channels and in line with the grooves '11. It will further be'observed from referthe inner faces of the bits are beveled or inas shown at 27.

In the bore 6 ofthe mandrel, a longitudinally movable plunger or stem 28 is mount-- 29 is mounted upon the yieldingly holdssaid stem against movement. The lower end of der 30 while the upperend thereof bears against the head 31 formed upon the upper The lower end of the stem opening 32, and each of the cutting bits is provided in its shank '19 with a similar opening 33 which is adapted to re 'ster with the opening in said stem. The fi key 34 is insertible through the registering openings of the stem and the bit shanks and is provided in one edge and at its center with a notch 35 to receive the stem28'at the lower end. of the opening 32 therein, said notch providing shoulders to prevent longitudinal movement of ours, however, thatthe the operation of and the bits will fall coupling pin or key the device coinciding openings which open into at rectangular downwardly in the. mandrel and swing outwardly therefrom or become entirely disengaged from the manthis spring bears against the internal shoulthe key; It often oc- 38 formed through the i e bit thanks it will thus be apparent that even if the key 3a is broken, the cutting bits when contacting with the side of the well hole will be forced upwardly so that the shoulders of the bit will engage with the shoulders on the lower end of the mandrel as above explained, thus holding said .bits against outward swinging movement, and enabling the same to sustain Various strains to which they may be subjected, in the continued operation of the reamer.

' In the use of my improved underreamer for reaming the walls of wells beneath the casing or well tube, the cutting bits are pulled downwardly against the tension of the ribs 26 on the bit shank the spring 29 so that said bits may be moved inwardly toward each other and beneath the Web plate 14 on the lower end .of the mandrel. This inwardmovement of the bits is permitted by the provision of the beveled surfaces 27 9n the inner faces of the shanks of the cutting bits and byflaring the lower ends of the grooves 11 of the mandrel which admits of the movement in said grooves of For the purpose of ulling' the bits beyond the end of the man rel so that the bits may be inserted in the upper end "of the well casing, a pair of tongs are employed, the jaws of which are adapted to be engaged in the sockets or recesses indicated at 39 which are provided in the outer face of each of the cutting bits. After disposing the bits in this manner, are inserted into the well tube and forced downwardly therein, the upward pull upon said bits exerted by the spring 29 tending to move the bits outwardly into frictional contact with the well casing. After the shoulders 21 of the cutting bits move beneath the lower end of the well tube, the spring 29 immediately acts to force the stem 28 upwardly in the mandrel and throw the body portions ofthe bits outwardly upon opposite sides of the web plate 14 and into engagement with the walls of the well. When the bits are extended, the key is disposed in the widened-lower ends 10 of the slots 9, and in the outward movement of the bits upon opposite sides of the web 14, this key is freely movable in said widened portions of the slots, thus obviating liability of breakage of the key and also facilitating movement of the bits into the lower end of the well tube when the reamer is drawn upwardly. When the reamer is rotated in the ordinary manner, the well will be reamed or cut away beneath the lower end of the easing. As above stated, the lapping flanges 18 serve to break u the material at the bottomof the well ho e which may accumulate beneath the cutting bits, and revent said bits from being clogged so t at the reaming operation 'mayxbe quickly comleted. p From the foregoing, it will be readily seen they that I have materially improved the construction of the device disclosed in my prior patent hereinbefo're referred to. When the operation is completed, the reamer may be readily withdrawn by simply pulling upwardly upon the same. The shoulders 21 of the cutting bits engaging the lower end of the well tubing holds said hits while the mandrel moves upwardly Within the lower sharpen the cutting bits. My improved reamer is also extremely durable and eflicient in practical use and may be produced at small cost.

While I have shown and describedwthe.

-present preferred embodiment of the invention, it will be obvious that the same is susceptible of considerable modification in the form, proportion and arrangement of the several elements without departing from the essential features or sacrificing any of the advantages thereof.

Having thus described the invention, what is claimed is:

1. In an underreamer, a longitudinal bore and channel on opposite sides of said bore, the body of said reamer being further rovided with longitudinal slots of less width than the channels and connecting the same with said bore, the lower ends of said slots being of greater width than the upper portions thereof, cuta mandrel having tingloits movable in sald channels, a removpressed stem mounted in the bore 0 able key connecting said cutting bits and movable into the wider lower ends of said slots when the bits are extended, a s ring pressed stem mounted in the bore o the mandrel, said stem being provided with an opening to receive said key, and means on themandrel to forcesaid cutting bits outwardly in opposite directions when the same are moved in one direction in said channels. 2. In an underreamer, a mandrel having a longitudinal bore arld channels on opposite sides of saidbore, the body of said reamer being further provided with longitudinal slots connecting said bore with the channels, the lower end portions of said slots graduall increasing in width, cutting bits movab e in the channels in said mandrel, a s ring t e mandrel, said stem and the cuttingbits havllt C3 oeoeeo ing rectangular openings corresponding in size and adapted to be brought into registerin relation, and a removable key to detachment in the opening in S3116. stem, said key being movable m the wfler lower cand e oi,

said slots when the bits are in their extend.- efl positions. 1o

Iii testimony whereof I hereunto afix my signature in the presence of two Witnesses.

WARREN WAGNER.

Witxiessesz. 

